The invention relates to a tailstock for a lathe comprising a housing in which a sleeve is seated, the sleeve being axially displaceable by means of a spindle.
1. Prior Art
A tailstock is a centering and clamping device for the workpiece, which centering and clamping device is displaceable on and is to be clamped in place on the lathe bed. It serves, for example, as a counterstay during the turning of a workpiece. During drilling work on the lathe, it is used as a clamping device for the drilling tool. In the process, the drill feed is effected by axial displacement of a tailstock sleeve, which can be effected manually or mechanically. The tailstock sleeve is normally driven by means of a screw spindle actuated by a handwheel. The sleeve in known tailstocks is in principle only axially displaceable, rotation being prevented by slot and sliding piece. After the sleeve is displaced by means of the drive spindle, the latter is clamped, for example, by means of a hand lever.
To carry out the rotary movement of the workpiece, the lathe center or tailstock center inserted into the sleeve must be of rotatable construction, since the sleeve itself, accommodating the lathe center, performs no rotary movement. In the simplest case, the lathe center is therefore constructed so as to be rotatably mounted relative to its clamping shank.
In large machine tools, the lathe center or other tools are inserted into complicated intermediate mounting fixtures for holding or machining the workpiece, which intermediate mounting fixtures assume the pivot-bearing function between sleeve and, for example, lathe center. Since machines of this type work with very high axial forces, which, for example, can amount to 80 t, an elaborate bearing arrangement in a radial or axial direction of these intermediate housings is necessary in order to perform the rotary movement. On account of the play and tolerances associated therewith in the mountings, a number of disadvantages result.
2. Advantages of the Invention
The invention has considerable advantages over the known tailstock designs. On account of a greatly simplified design, a complicated construction with regard to a radial and axial bearing arrangement can be avoided.